Transmission mechanism



April 6, 1948.

W. HOWALD TRANSMISSION HECHANISI Filed Sept. 11

. 1944 5 Sheets-Sheet 1- April 6, 1948.

w. How/3L0 TRANSMISS IQ MECHANISM Filed Sept.

11, 1944 '6 Sheets-Sheet 2 III-r P 1 w. HOWALD TRANSMISSION MECHANISM Filed Sept. 11, 1944 6 Sheets-Sheet 3 w. HOWALD TRANSMIS SION MECHANISM 6 Sheets-Sheet 4 Filed Sept. 11. 1944 April 6, 1948. w. HOWALD 2,439,003

TRANSMISSION HECHQNISM 7 Filed Sept. 11, 1944 Y 6' Sheets-Sheet 5 P 1948- w. HOWALD 1 2,439,003

TRANSMISSION MECHANICS! Filed Sept. 11; 1944 6 Sheets-Sheet 6 Fig, 78

Patented Apr. 6, 1948 UNITED STATES PATENT OFFICE I 2,439.00:

TRANSMISSION MECHANISM Werner Howald, Zurich, Switzerland Application September 11, 1944, Serial No. 553,583

In Germany September 14, 1943 The present invention relates to a new and improved two stroke combustion engine with tubular slide valve and more particularly to the specific means to actuate the tubular slide.

The main object of the invention consists in the provision of simple means to attain a high precision of the tubular valve movements at any speed, said means taking up but little space.-

With these and other objects in view the invention consists in the particular construction and arrangement of parts as described in the following specification and set out in the claims.

In the accompanying drawings:

Fig. 1 shows part of the cylinder of a twostroke combustion engine with tubular slide valve and the operating gear therefor in sectional elevation.

Fig. 2 is a cross-section on the line 2-2 of Fig. l. i

Fig. 3 shows the valve gear t-t of Fig. l, and

i is a cross-section taken on line t--4 of Fig.

Figs. 5 and 6 are sections taken on the same lines as in Figs. 3 and t but showing the parts of the valve gear in a, modified position.

Figs. 7 and 8 are again cross-sections as shown in Figs. 3 and l showing the parts of the valve gear with the piston at its lower dead point positlon.

Fig. 9 shows in cross section parts of the valve gear taken on line 9-liof Fig. 10 illustrating the assembling of parts.

Fig. ill is a horizontal section on line te th of Fig. ll parts being omitted.

ll illustrates partly in section on line t l i l of it and partly in elevation a follower attached to the tubular slide valve.

Fig. i2 is a section taken on line ill-4t of Fla. 10 showing the attachment of the follower to the tubular slide valve.

Fig. 13 is a side elevation of a connecting member interconnecting the tubular slide valve with in a section on line the cam shaft.

Figs. it, 15 and 16 show in cross-section and in plan view and in side elevation respectively the crank slide.

Fig. 17 is a side view of part of the cam shaft.

Figs. 18 and 19 illustrate in sectional elevations of the engine the operation of the valve gear.

Figs. 20 and 21 are sections taken on the lines bit 20-20, ll-2l of Fig. 18, parts of the gear bein 6 Claims. (c1. ri -so) connected to the tubular slide valve, 4 denotes a crankshaft with an eccentric 4e, the latter carry-- ing a crank pin 4d. On the crank pin 4d! a con necting member 5 is rotatably mounted. The connecting member 5 (Fig. 1) is provided with ball shaped bearing faces 5a, 5b sliding on bail shaped faces to and 3b of the follower 3. On the eccentric 4e a, slide 6 with bore lie is rotatably mounted (Figs. 1, 14 and 15) having two parallel straight cylindrical bearing faces (Figs. 15, 16) fitting into the cylindrical bearing faces 3c (Figs.

. 4, 9, 10) of follower 3. The crankshaft 4 runs in ball bearings I of the engine frame 9. The follower 3 is connected to the tubular slide! by ton it of the engine. The piston I4 transmits not only work done by the expanding gases in the cyliiider l onto the crankshaft l2 but it governs the inlet of fuel into cylinder by its upper edge No in combination with the inlet slots D in the tubular slide 2 and the slots B for the scavenging air and the slots 0 of cylinder l for the overcharge. The exhaust of the gases from the combustibn space is controlled by the upper edge 20 of the tubular slide 2 co-operating with the exit slots A in the working cylinder 5. I

The manner of operation of the new, drive for the tubular controlling slide 2 isillustrated in Figs. 3 to t. The tubular slide it is rigidly connected to the body of the follower 3 by three screw bolts t running parallel to the axis Z of the cylinder l. Thetubular slide 2 and the follower 3 are not only freely movable in the bore of the cylinder l parallel to its axis but they are moreover freely rotatable about the cylinder axis Z. The tubular slide 2 is moved by the crankshaft l, the member 5 and the slide 6. In

the position of the parts shown in Figs. 3 and a, the tubular slide 2 with the follower 3 and the parts 5 and 6 are in their uppermost dead point position. The axes Zd of the crank pin 4d, Ze and Z5 are in one common plane passing through the axis Z of the cylinder 5' and through the axis Z4 of the crankshaft 4.

In the position of the parts shown in Figs; 5 and 6 the crankshaft 4 has been turned for about and therewith the eccentric 4e. The throw R4 of the crankpin 4d and the throw 14 of the eccentric 4e has been moved out of their upper dead point position into their outermost sideward position out of the plane passing through the axis Z of the cylinder I and the I 3 axis Z4 of the crankshaft 4. The tubular slide 2 and therewith the follower 3 have been turned about an angle p out of their middle position, while the tubular slide 2 andthe follower 3 have been moved downwardly by the connecting membet 6 in conformity to the downward movement running parallel to the axis Z of the working of the centre Z5 of the connecting member 5.

The centre Z5 of the connecting member Ii which forms a fast point relative to the tubular slide 2 and the follower 3 passes thereby through the points I,' 2, 3 of the path Q (Fig. 5). The slanting position of the follower 3 which is thereby produced relative to the crankshaft 4, the member 5 and the slide '6 is possible owing to the ball shaped faces of the member 5 and the cylindrical bearing faces to of the slide 6 and 3c in the follower 3. The latter as well'as the slide 8 perform simultaneously a small axial displacement on their cylindrical gliding faces 4d and 46 on the crankshaft 4, as the centre Z5 of the ball shaped face 5a, 5b, viz. 3a, 3b as well as of the axis Z6 cylindrical running faces '30, 8c of the follower 3 and of the slide 6 in a circular path round the axis Z of the cylinder.

In the Figs. '7 and 8 the parts are shown in that position which they have attained by turning the crankshaft 4 for another 90. The parts have attained their lower dead point positions and their axes are again in a common plane passing through the axis of the cylinder I and g the axis of the crankshaft 4. The centre Z5 of the connecting member 5 has passed on over the points 3, 4 and 5 of the path Q into the lower dead point position.

From Figs. 9, 13,14,15 it might be seen by the arrows how the connecting member 5 and the slide 6 and the crankshaft 4 and the follower 3 are assembled. As illustrated in Fig. 9 the connecting member 5 is placed on to the ball shaped face 30 of the follower 3 in inserting it from the side of the tubular slide 2 in nearly horizontal position and with the small ball face 5b in advance. The member} is then turned into the vertical working position. The member 5 with its ball shaped bearing faces 5a, 5b fits into the corresponding ball shaped bearing faces 3a and 3b of the follower. The slide I I5 is now inserted from the top or from below into the follower 3 so that its cylindrical bearing faces 60 pass into the cylindrical bearing faces of the follower 3. Now the pin of the crankshaft 4 is inserted (Fig. 17) with its cranked part in advance through the bore 60 of the slide 6 until the cylindrical crank pin 4d enters the cylindrical bore 511 of the connecting member while the cylindrical shank 4a comes to rest in the cylindrical bore of the slide 6. By placing all theksaid parts from below into the working cylinder I and by securing the crankshaft 4 in its bearings 1 of the machine frame 9 as illustrated in Fig."9 the whole drive will be assembled.

From the above said it appears that the ball shaped faces 5a and 5b envelop the cylindrical bearing faces of the crank pin 4d and that the,

cylinder I runs not through the middle of the slide 6 but is placed out of centre into that portion nearer to the tubular slide 2.

The controlling of the outlet and inlet ports is shown in the diagram, Fig. 22, and in the'Figures 18, 19, 20 and 21. In the diagram shown in Fig. 22 the time of a whole turn of the crankshaft I2 is marked by horizontal lines and on vertical lines are noted the position of the co-operating edges of the ports of cylinder I of tubular slide 2 and of working piston I4. The stationary edges of the cylinder I appear, as straight horizontal lines parallel to the axis denoting time while the movable controlling edges of the tubular slide 2 and of the working piston I4 appear as curved lines. The arrow denotes the direction of rotation of the crankshaft I2, and the crankshaft 4. The ordinates in the vertically shaded parts a, b, 0 indicate the dimension of the open cross sections which multiplied by the corresponding breadth give the cross section area of the exit A for the exhaust gases of the inflow B of the scavenging air and of the entry C of the supercharged air or of the supercharged mixture of air with fuel. 0T2 is the outer and UT2 the inner dead point of the tubular slide 2; OTI 4 is the outer and UTI4 is the inner dead point of the working piston I4. The stroke of the slide 2 is denoted by s2 and the stroke of the. working piston I4 is denoted by 3. The point of the maximal speed of the tubular slide 2 is marked with W. F denotes a point of maximal decrease or increase of the speed of the tubular slide 2 in advance or after the outer dead point.

The piston I4 is moved by the pressure of the ignited charge from the upper dead point 0TI4 towards the lower dead point UTI4 and drives by means of the connecting rod I3 the crankshaft I2. The tubular slide 2 is turned in the same direction as the crankshaft I2 in advance by an angle a.- At about Va of the whole stroke in advance of the lower dead point UTI4 of the working piston I4, the upper edge 20 of the tubular slide 2 and the stationary uppenedge A0 of the exhaust port A-meet (Fig. 22, point P1). As tubular slide 2 has attained at'this zone its greatest speed (Fig. 22) the gap between the upper edge of the tubular slide 2 and the upper edge A0 of the exhaust ports A is quickly increased. The exhaust gases pass with but little throttling loss through the outlet A either to the blades of the running wheel of a turbine or.

directly by means of repulse nozzles into the at- .mosphere. As the pressure in the working cylinder I decreases to the pressure of the scavenging air the upper edge I40 of the working piston I4 meets the upper edge D0 of the inlet-slots D in the tubular slide 2 and the stationary upper edge B0 of the slot B for the inlet of the scavenging air into the working cylinder I (Fig. 22, point P2). At this zone the speed of the working piston I4 is in excess of the speed of the tubular slide 2 the width of the open portion between the upper edge I4 of the working piston I4 and of the upper edge D0 of inlet slot of the tubular slide '2 increases very quickly. The remaining gases of the combustion in the combustion space will be swept out by the scavenging air entering through the slots A. The scavenging of the gases of combustion is keeping on until the tubular slide 2 and after that the working piston I4 have passed their dead point positions and until the tubular slide 2 has reached and passed over by its upper edge 20 the upper edge of the exit slot A of the working cylincylinder I being closed by the tubular slide 2.

Shortly before the closing takes place the inlet slot D of the tubular slide 2 opens the ingress of the supercharge, of air or of supercharge and airfuel-mixture through the slots C in the cylinder I. By closing theslots B for the scavenging air after the exhaust slots A and owing to the fact that the tubular slide 2 has reached its speed in its upward direction, the ingress slots -B for the scavenging air are closed very rapidly while the working cylinder I has received its charge before the supercharging is performed. At the same time or shortly in advance the slots for the supercharging of air or of air-fuel-mixture had been opened (Fig. 22, points P4 and P5). At about of its stroke in advance of its upper dead point O'I'll the working piston I4 has again reached with its upper edge M0 the upper edge D0 of the inlet slots D of the tubular slide 2. The infiow of supercharge air or of supercharge air-fuel mixture into the working cylinder I is closed by the passing over of the upper edge Co over the slots 0 for the influx of the supercharge (Fig. 22, point Pa). As the working piston M has attained its highest speed during its upward stroke at this zone and as the speed of the tubular slide 2 is nearly at zero, the closing of the supercha'rg'ing slots C takes place very quickly. a

What I wish to secure by U. S. Letters Patent is:

1. In a driving mechanism, the combination comprising a crank shaft provided with an eccentric disc and a crank pin on said eccentric disc, a follower fixedly attached to a driven member and provided with two pairs of axially spaced bearing surfaces, a slide rotatably mounted on said eccentric disc and slidably engaging one pair of said bearing surfaces on said follower, and a connectingmember rotatably mounted on said crank pin and slidably engaging the other pair of said bearing surfaces on said follower.

2. In a driving mechanism, the combination comprising a crankshaft provided with an eccentric disc and a crank pin on said eccentric disc, a follower fixedly attached to .a driven member and provided with a pair of concentrically ar-' ranged cylindrical bearing surfaces and axially spaced therefrom with a pair of spherical bearin: surfaces, a slide rotatably mounted on said eccentric disc. andvslidably engaging said pair of cylindrical bearing surfaces on said follower, and a connecting member rotatably mounted between its ends on said crank pin and having both its ends provided with spherical bearing surfaces engaging the spherical bearing surfaces on said follower.

3. In a drivingmechanism, the combination comprising a crankshaft provided with an eccentric disc and a crank pin on said eccentric disc, a follower fixedly attached to a driven member and provided with a pair of concentrically arranged cylindrical bearing surfaces and axially 6 provided with spherical bearing surfaces engag ing the spherical bearing'surfaces on said follower, the total length of said connecting member between the spherical end faces thereof being less than the diameter of said eccentric disc.

4. In a driving mechanism, the combination comprising a crankshaft provided with an eccentric disc and a crank pin on said eccentric disc, a follower fixedly attached to one end of a cylindrical driven member and provided with two pairs of axially spaced internal bearing seats, one pair of said bearing seats being cylindrical and arranged concentrically and equidistant about an axis extending parallel to the axis of said sleeve member, the other pair of said bearing seats being spherical and having different radii of curvature, a slide rotatably mounted on said eccentric disc and having exterior cylindrical bearing surfaces which slidably engage the pair of cylindrical internal bearing seats on said follower, and a connecting member rotatably mounted on said crank pin and having a pair of exterior sphericalbearing surfaces in operative engagement with said pair of internal bearing seats on said follower.

5. In a driving mechanism, the combinatio comprising a crankshaft provided withan eccentric disc and a crank pin on said eccentric disc, a follower fixedly attached to one end of a cylindrical driven member and provided with two pairs of axially spaced internal bearing seats, one pair of said bearing seats being cylindrical and arrangedconcentrically and equidistant about an axis extending parallel to the axis of said driven member, the other pair of said bearing seats being spherical and having different radii of curvature, a slide rotatably mounted on said eccentric disc and having exterior cylindrical bearing surfaces which slidably engage the pair of cylindrical internal bearing seats on said follower, and a connecting memberrotatably mounted between its ends on said crank pin, the ends of said connecting member having spherical bearing surfaces matching and engaging the spherical bearing seats on said follower, the total length of said connecting member between the spherical bearing faces thereof being less than the diameter of said eccentric disc, and the axis of said crank pin being arranged closer to the spherical bearing surface having the greater radius of curvature than to the spherical bearing surface having the smaller radius of curvature.

6. In a driving mechanism, the combination comprising a crankshaft provided with a disc and a crank pin on said disc, a follower fixedly attached to a driven member and provided with two pairs of axially spaced bearing surfaces, a slide rotatably mounted on said disc and slidably engaging one pair of said bearing surfaces on said follower, and a connecting member rotatably mounted on said crank pin and slidably engagspaced therefrom with apair of spherical bearing the other pair of said bearing surfaces on said follower.

WERNER HOWALD.

REFERENCES crran UNITED STATES PATENTS Name Date 1 Number Kipfer Oct. 25. 1938 

